Objectives ecs rework (#19967)

Co-authored-by: deltanedas <@deltanedas:kde.org>

Content.Server/Objectives/Components/ObjectiveBlacklistRequirementComponent.cs

@@ -0,0 +1,15 @@
+using Content.Server.Objectives.Systems;
+using Content.Shared.Whitelist;
+
+namespace Content.Server.Objectives.Components;
+
+/// <summary>
+/// Requires that the objective entity has no blacklisted components.
+/// Lets you check for incompatible objectives.
+/// </summary>
+[RegisterComponent, Access(typeof(ObjectiveBlacklistRequirementSystem))]
+public sealed partial class ObjectiveBlacklistRequirementComponent : Component
+{
+    [DataField(required: true), ViewVariables(VVAccess.ReadWrite)]
+    public EntityWhitelist Blacklist = new();
+}